Oil palm (Elaeis guineensis Jacq.) is one of the most important economic crops for Malaysia. In year 2002, plantation area for oil palm covers around 3.7 million hectares. Apart from that, Malaysia is the world's largest producer and exporter of palm oil with a 50% share of world's palm oil production and 61% share of exports (Chang et al., 2003).
Agrobacterium tumefaciens is one of nature's most successful organisms for genetically engineering plants and is routinely used to transfer desirable genes into dicotyledon plants. Agrobacterium-mediated transformation are relatively efficient and a low copy number of intact, non-rearranged transgenes can be integrated into the plant genome (Gelvin, 1998). Later, successful transformation of monocotyledon plants using Agrobacterium-mediated transformations have been achieved (Hiei et al., 1994; Rashid et al., 1996; Ishida et al., 1996). Inefficiency of transformation of monocotyledon plant species was thought caused by lack of production of virulence inducing substances (Usami et al., 1987; Sahi et al., 1990). The development of this method to transfer the gene(s) of interest into monocot plants was thought to be a bottleneck since these plants are not the natural host for Agrobacterium. 
The known method for transforming cells of an oil palm with genetic material to produce a genetically-modified and regenerated oil palm plant is by (i) obtaining embryogenic calli from oil palm cabbage, (ii) transforming embryogenic calli, (iii) selecting for transformed calli, (iv) maintaining transformed calli for a time and under conditions sufficient for the formation of polyembryogenic calli cultures and (v) regenerating transformed plantlets from polyembryogenic calli culutres.
Studies are ongoing to modify this monocot plant through genetic engineering to improve the quality of palm oil (Parveez et al., 1999). Previously, microprojectile bombardment was chosen as the preferred method for transformation of monocot plants (Christou, 1996).